Some folks have a love-hate relationship with gifts. They might love the sentiment of a gift, but they hate bringing "stuff" into their lives. It can happen for various reasons: an environmentalist might be concerned with the earth impact of that stuff, someone who is trying to reach material simplicity might be philosophically and emotionally opposed, and sometimes a parent just wants to avoid a glut of plastic toys at the holidays.
People deal with it in various ways: just accept the gifts, ask for no gifts, ask for donations to charity, or entirely avoid the occasion (by not having a birthday party, for example). Some of these work better than others. For example, every time I've been invited to a child's birthday party that said "no gifts" on the invitation, at least a few gifts show up. Then the people who brought the gifts may feel bad that they didn't realize not to bring gifts, the people who didn't bring gifts may be kicking themselves saying "I knew I should have brought a gift anyway", and so on.
In the ideal case, a gift is meaningful, useful, and appreciated by the recipient, and then both the giver and receiver feel good about the gift.
I think that being really explicit about what gifts would be meaningful, useful, and appreciated is alternative way to approach gift giving. After all, even the most fanatical stuff avoider has something they like: maybe a particular type of wine, or maybe tickets to a show. A few years ago, I realized my life was so busy, I had no time for gifts that took time (like a new game or activity), but if a gift fit into an activity I was already doing and made it better, then I greatly appreciated it. That year I asked for quality cookware to replace some of the older pots I had that weren't so great. Another year I had no time to think about gifts before the holiday, but I knew that I would want to go clothes shopping later in the year, so I asked for REI gift certificates.
The point is, most people can think of things that would be meaningful, useful, and appreciated. So instead of hiding under a rock at Christmas, just tell people what you would really like.
One way you can make and communicate a wishlist is by using a tool like
Magic Wishlist, which is a wishlist application for Facebook. Then your friends and family on Facebook can easily find your wishlists. Wishlists can include items from any online store, and you can link to charities if you want to solicit donations instead of gifts. (Wishlists also include a handy url you can share with family who might not be on Facebook, or that you can include in an e-invitation to a birthday party.)